Improving crop resilience, yields in a world of extreme weather

conditions and close the stomata.  Inside plant cells, ABA does its job by turning on a special class of proteins called receptors.  The discovery in 2009 of ABA receptors by the same team behind the current breakthrough was heralded by Science magazine as one of the top breakthroughs of 2009 because of its relevance to the drought problem.

“If you can control the receptors the way ABA does, then you have a way to control water loss and drought-tolerance,” Cutler said. “It has been known for many years that simply spraying ABA on plants improves their water use and stress tolerance, but ABA itself is much too expensive for practical use in the field by farmers.”

To address this problem, Cutler and his team searched through many thousands of molecules to identify inexpensive synthetic chemicals that could activate the receptors by mimicking ABA. The team found and named quinabactin, a molecule they show is almost indistinguishable from ABA in its effects, but much simpler chemically and therefore easier to make than ABA. By studying how the new molecule activates the ABA receptors that are involved in drought tolerance, the team also has learned more about the underlying control logic of the stress response system and provided new information that can be used for others interested in developing similar molecules.

“This is a competitive arena that includes agrichemical giants who are busily working to bring similar drought-protecting molecules to market, so this is a landmark discovery because quinabactin is the first-in-class synthetic molecule of its kind,” Cutler said.

The release notes that the work reported this week is the first in a multistep process of bringing a new agricultural product to market. Given the complexity and costs of such a process, the UCR Office of Technology Commercialization (OTC) is working with an agricultural leader, Syngenta Biotechnology, Inc., to develop the technology.

Joyce Patrona, a licensing officer in OTC, is coordinating UCR’s licensing efforts for quinabactin.

“It has become very apparent to industry engaged in this area of technology of the robustness of Dr. Cutler’s research,” she said.  “This is a credit to Dr. Cutler and his team as well as to UCR for its commitment to bring innovative research to the marketplace.”

The research was supported by grants from the National Science Foundation, Syngenta Biotechnology, Inc., and the Japanese Society for the Promotion of Science.

— Read more in Masanori Okamotoa et al., “Activation of dimeric ABA receptors elicits guard cell closure, ABA-regulated gene expression, and drought tolerance,” Proceedings of the National Academy of Sciences (1 July 2013) (doi: 10.1073/pnas.1305919110)